Both of the actors (Peterson & Guilfoyle) no longer wanted to be on the show. It’s time to accept it, and stop with the “bring back –” all the time. Actors tire of roles, and as much as it may piss fans off, I’d rather see an actor who still loves the role they play, rather than one who doesn’t like it anymore and phones it in.

Petersen left of his own accord, but Guilfoyle was showed the door; ie, not asked back. Sorry treatment for someone there since the beginning. CSI sucks now anyway, so may be best thing for his career. The season finale will be Brass’ last episode.